Acute bacterial rhinosinusitis is the mucosal inflammation of the nose and paransal sinuses caused by bacteria lasting >10 days for up to 4 weeks or symptoms worsening for 5-7 days and is <12 weeks with complete resolution of symptoms.
It is often preceded by a viral upper respiratory tract infection.
Signs and symptoms are nonspecific and typically difficult to differentiate from viral upper respiratory tract infection.
There is fever with nasal obstruction/congestion or anterior and/or posterior purulent drainage, with or without facial pressure/pain/fullness and reduction/loss of smell.Streptococcus pneumoniae and unencapsulated strains of Haemophilus influenzae cause half of acute rhinosinusitis cases.

Factors that predispose patients to antibiotic-resistant bacteria need to be considered (eg antibiotic usage within the past month, hospitalization in the past 5 days, age <2 or >65 years, exposure to daycare, comorbid conditions, impaired immune response, severe infection, living in areas with high rates of resistance)

Goals of Antibiotic Therapy

Eradicate bacterial infection from the sinuses

Hasten resolution of symptoms

Prevent complications

Decrease the development of chronic disease

Pharmacotherapy

Mild Disease and No Antibiotics Within the Last 4-6 Weeks

In patients who have not responded to symptomatic therapy alone or those whose symptoms have worsened

Amoxicillin (Usual or High Dose)

Amoxicillin continues to be the agent of choice for ABRS due to its safety, efficacy, low cost and narrow microbiologic spectrum when still effective in the locality

In areas with high incidence of resistant S pneumoniae, high-dose Amoxicillin should be considered

Generally considered the most active of all oral beta-lactams against streptococci and only S pneumoniae that is highly resistant to Penicillin will not respond to conventional doses of Amoxicillin

Activity against beta-lactamase-negative strains of H influenzae is fair to good but it is ineffective against beta-lactamase-producing strains

Amoxicillin/Clavulanic Acid with or without High-Dose Amoxicillin

Recommended as initial empiric therapy for ABRS rather than Amoxicillin alone

Recommended in patients with moderate to severe disease who have failed high-dose Amoxicillin or if beta-lactamase-producing strains of H influenzae, M catarrhalis or oral anaerobes are suspected

Amoxicillin may be added to Amoxicillin/clavulanic acid to overcome drug resistance of S pneumoniae and should be considered in areas with high incidence of resistant S pneumoniae

Cephalosporins (2nd and 3rd Generation)

Eg Cefaclor, Cefdinir, Cefixime, Cefuroxime, Cefpodoxime, Ceftriaxone

Alternative agents that may be considered for patients with ABRS who have non-type 1 allergy to Penicillin

Because of variable resistance to S pneumoniae, it is not recommended for single-agent empiric therapy

Local resistance patterns and antimicrobial spectrum of the cephalosporins to S pneumoniae, H influenzae and M catarrhalis will need to be considered prior to choosing an agent

Because of the potential for increased resistance and toxicity, these agents should be reserved for adults with type 1 allergy to Penicillin and risk factors for resistant organisms, moderate disease, or in those who have failed recent antibiotic coverage

Most patients with ABRS that have been treated with the appropriate antibiotic agent will show clinical improvement within 48-72 hours

If ABRS is worse within 72 hours after initiating treatment:

If initially advised further observation, may start Amoxicillin with or without Clavulanate therapy

If initially prescribed with Amoxicillin, may increase dose and may add Clavulanate

If initially prescribed with high-dose Amoxicillin-Clavulanate, may shift to Clindamycin + Cefixime OR Linezolid + Cefixime OR Levofloxacin

No clinical improvement seen after 72 hours:

If initially advised further observation, may start antibiotic therapy

If initially prescribed with Amoxicillin, may initiate high-dose Amoxicillin/Clavulanate therapy

If initially prescribed with high-dose Amoxicillin-Clavulanate, may continue giving high dose Amoxicillin-Clavulanate OR may shift to Clindamycin + Cefixime OR Linezolid + Cefixime OR Levofloxacin

In patients without severe ABRS and comorbidities, they may benefit from short-course treatment which leads to better compliance, fewer adverse effects, lower resistance rates and lower costs of medications

Short-course treatment with appropriate oral antibiotic treatment is given in 7 days

May be extended to 14 days if symptoms fail to resolve

The duration of antibiotic therapy in patients with moderate to severe ABRS is 7 to 14 days